I don’t know what you mean by microwave trials.
They exist as both waves of electrical field and magnetic field. They do travel through materials that allow them to pass through. This interaction depends on things like whether there’s an electron that has an orbital transition that matches the energy of the passing wave. But you can tell that they don’t need the molecules because they can go through vacuums, unlike physical vibrations like sound or ultrasound.
Capta real quick for me. Send me back the zap I just sent. 🫂